pacemaker & Extrasystole

Artificial pacemaker must be used when the heart depends on:

• AVN rythm

• primary pacemaker cells

• Purkinje fibers rythm

• beats with 60 b/min

The shown picture may represent AP of all the following except:

• conductive cardiac muscles

• SAN

• main atrial and ventricular bulks

• specialized cardiac muscles

if the waves on the left represents normal cardiac muscle contractions, the shown effect on the right may be caused by:

• local application of beta blockers

• local application of adrenaline

• fever

• thyrotoxicosis

In patients receiving atropine, you expect their HR to be:

• 70-75 bpm

• 90-110 bpm

• 30-40 bpm

• 120 bpm

the shown picture represents :

• ventricular ectopic focus

• atrial ectopic focus

• atrial fibrillation

• AV nodal rythm

which of the following is caused by accumulation of Ca ions from the missed beat ?

• extrasystole

• compensatory pause

• premature beat

• post extrasystole potentiation

causes of extrasystole may involve all of the following except:

• thyrotoxicosis

• receiving digitalis

• sleep deprivation

• excess coffee intake

if the atria are stimulated at the diastole, which of the following pictures you expect to see?

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stimulation of the ventricles during systole may show which of the following?

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